West Control Solutions KS 800 Profibus Interface Manual - Manual (Page 46)

6.2 Function module for SIMATIC ® S7
The S7-FB handling principle corresponds to the S5 variant. When starting an order and as long as the order
is active, calling up the FB is indispensable.
Dependent of S7-CPU and DP-Master, the I/O handling is different. With a CPU315-2 DP with on-board DP
interface, SFC modules 14 and 15 must be used for consistent data transmission. SFC modules 14 and 15
copy the I/O areas into the marker or data module area. When using an external CP (CP 342-5 DP), the
relevant DP-SEND and DP-RECEIVE FBs at the cycle start and end must be called up.
The FB has an instance DB, which must also be specified with FB call.
6.2.1 Structure
The call parameters of the function module are:
Name Type Description / function
A-start Pointer Output word address area start (e.g. address data area ‘RECORD’ of SFC 15, Ax, y when using an
external CP). The DB no. must also be transmitted when specifying a data word (e.g. DB4.DBX0.0)
E-start Pointer Input word address area start (e.g. address data area ‘RECORD’ of SFC 15, Ex, y when using an
external CP). The DB no. must also be transmitted when specifying a data word (e.g. DB4.DBX0.0)
DB-Para Pointer
Specification of data module with the parameter setting data. The entry comprises the data module
no. and the data word no. at which the parameter data start. Thereby,no offset needs being taken
into account. The data are interpreted as parameter data (useful data) by the specified address. The
DB must be specified in the following form e.g. DB6.DBX10.0
Service WORD Service (Read/Write)
Code_nr WORD Code
FB_nr WORD Function block no. (channel addressing)
FKT_nr WORD Function no.
Typ WORD No function (always ‘0’)
Timeout DWORD Timeout value, is decremented with each call. With a value of = 1, the order is cancelled with error
message ‘timeout’.
DWLR WORD Length of real values
DWLI WORD Length of integer values
DWLC WORD D.c. always ‘0’
ANZW W
The current transmision status for the selected data area is given in the display word. The structure of
the display word is:
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Timeout
(FB)
Service
faulty
NAK
(access
by
controller
not
accepted)
Parity
error
Timeout
internal
(controller)
Waiting
for
end
telegram
Service
(0=Read;
1=Write)
Reset
order
Waits
for
acknowledgement
Order
finished
with
error
Order
finished
without
error
Order
running
The function module reads or writes KS800 parameter/configuration data.
w A-start, E-start
The parameter channel input addresses or output addresses are entered into these parameters. The
addresses are determined during configuration of the unit connected to the PROFIBUS (STEP 7 -
hardware configuration)
w DB-Para
DB-Para is a pointer to the data module, into which read data are written or from which data are taken
when writing.
Function modules
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